The application of liquid crystal display cells to pocket size devices has been steadily expanding in scope and, as a consequence, the need for producing liquid crystal display cells having a reduced weight and thickness has been recognized. At present, liquid crystal display cells preponderantly use glass substrates, and since these glass substrates lose mechanical strength as the glass decreases in thickness, the manufacture of glass substrate display cells is difficult and the quality of produced display cells suffers. As the glass used in the display cell gets thinner, the glass flexes more easily and is more likely to break. Additionally, from an economic point of view, the price of a glass substrate increases as the wall thickness decreases. To eliminate these problems, a film of an organic polymer capable of taking the place of glass as the material can be used for the substrate. When an organic polymer film is used as the material for the substrates, the need to produce display cells of reduced weight and thickness is satisfied by display cells that will sustain external impacts, such as caused by a fall without breaking. Because the organic polymer film is flexible, it naturally follows that the display cells using substrates of this film are flexible. This type of film permits manufacture of display cells for curved surfaces of display cells having freely alterable surface properties which, at the same time, do not break when deformed. Since the substrates for the display cells must have a certain degree of transparency, thermal resistance. mechanical strength and stiffness, the polymer material used for the film is usually selected from among, for example, polyesters (biaxially stretched and monoaxially stretched grades), polyethers, polysulfons, polycarbonates, and phenoxy ether polymers.
FIG. 1 illustrates a prior art liquid crystal cell using a film made from an organic polymer for its substrates. On the inner surfaces of the polymer film substrates 1 and 4 are formed of an indium tin oxide ITO (In.sub.2 O.sub.3 +SnO.sub.2) film. Superposed on the transparent electrodes 3 and 4 are orienting films 5 made of, for example, SiO, SiO.sub.2, polyimide, polyimideamide, or polyvinyl alcohol, for orienting liquid crystal molecules. The orienting films 5 acquire the ability to orient liquid crystal molecules by, for example, being subjected to a rubbing treatment or to tilted vacuum deposition. Spacers 6 are uniformly dispersed on substrate 1 and a sealing agent 7 is deposited on substrate 2 by a screen printing technique. The two substrates 1 and 2 are then joined face to face forming a small gap therebetween for liquid crystals 8. The liquid crystals 8 are then injected into the cell thus formed and the injection hole for the liquid crystals is tightly closed with sealing resin 9.
When the liquid crystal cell fabricated, as described above, is left standing for a long period of time or is placed under conditions involving widely varying temperature changes, such as encountered in a temperature-humidity cycling test, the liquid crystal cell forms zones in which the two flexible film substrates 1 and 2 come into mutual contact and short circuits form between the electrodes 3 and 4. On the other hand, even through the occurrence of the short circuits could be prevented by, for example, inserting spherical spacers 10 .mu.m in diameter between the electrodes, the variation in the distance separating the electrodes after the cycling tests, etc. is distributed in the range of 10 .mu.m to 100 .mu.m within the same cell. As a consequence, the response time of the display cell varies greatly from one position to another across the surface of display cell and the quality of display cell may be seriously impaired. The variation in spacer distance can also occur when the cell is flexed. This adverse spacer displacement and electrode contact condition of prior art cells is depicted in FIG. 2. When first manufactured, spacers 13 are uniformly distributed between two substrates 11 and 12 made of the organic polymer film, as illustrated in FIG. 2(A). When the film substrates 11 and 12 are deformed, spacers 13 move out of their original positions and are redistributed nonuniformly. Consequently, zones develop in which the spacers 13 are sparsely distributed, as illustrated in FIG. 2(B), and the film substrates 11 and 12 are deformed and may come into mutual contact when under a slight exernal pressure. This type of contact can also occur in very thin glass substrate display cells which do not have spacers.